Could not load file or assembly

Question

I'm working on a system to use a SqlServerCe with NHibernate. From my driver program, if I add the System.Data.SqlServerCe assembly as a reference, I can create and run queries against a database just fine. When trying to use NHibernate, though, I get the following exception:

A first chance exception of type 'System.IO.FileNotFoundException' occurred in mscorlib.dll Additional information: Could not load file or assembly 'System.Data.SqlServerCe' or one of its dependencies. The system cannot find the file specified.

I've traced the exception to a call to Assembly.Load("System.Data.SqlServerCe"), which seems like it should work. The System.Data.SqlServerCe assembly is in the GAC (I've also tried to add it as a local reference with CopyLocal=true, to no avail), and I can use its members fine, so why can't I explicitly load it? When I open the assembly in Reflector, it has trouble loading the System.Transactions reference (I've also tried adding it as a local reference, again to no avail), so loading that assembly might be the problem, rather than the System.Data.SqlServerCe assembly.

Is this a common problem? System misconfiguration, maybe?

Answer 1

Apparently this can be solved by adding a <qualifyAssembly> element to the app.config file. Adding the following has my app running smoothly:

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <qualifyAssembly partialName="System.Data.SqlServerCe" fullName="System.Data.SqlServerCe, Version=3.5.1.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />
    </assemblyBinding>
</runtime>

Thanks!

Answer 2

This is most probably connected to some system (mis)configuration.

However, by design SQL Server CE is just a single DLL, which may be shipped together with your product.
This means that you can just set Copy local to True in the reference properties of System.Data.SqlServerCe, and you are done.